Information Technology

Communication Services

UofL Dynamic DHCP Conversion

The goal of this project is to convert the IP address assignment for the University of Louisville to a more dynamic assignment process. The advantages of this will be a more streamlined and less interactive process for obtaining access to the UofL network.

The IP address assignment is done using a protocol called Dynamic Host Configuration Protocol (DHCP). DHCP can assign addresses in a static or dynamic method, and assigns the IP addresses to an Ethernet address or Media Access Control (MAC) address. The static method will assign the same IP address to a MAC address each time an IP address is requested. The dynamic method may assign a different IP address each time one is requested, although it will reassign the same IP address, if it is available.

We use both of the methods on campus, requiring registration of the MAC addresses before accessing the network, except for some special cases, such as dorms and wireless. The normal, default, action is to use the static method, assigning an IP address in the appropriate building IP network. The dynamic method is used for devices/computers that need to access the wired network in multiple locations, such as laptops, that may need to be used in any building on campus. Domain Name Service (DNS) names for static IP assignments may be defined as the registrant specifies, such as mycomputer.mitc.louisville.edu. Dynamic addresses are generic pool names, such as dhcp034.mitc.louisville.edu. Some devices/computers require static addresses, such as servers (web, file, print), but most computers can use dynamic IP addresses with no problems, an example being home users who receive dynamic assignments from their Internet Service Provider (ISP). We do allow unregistered devices/computers on the wired network to receive a private, restricted to campus, IP address allowing them some access.

The first step in this process will be to change the default mode for assigning IP addresses from static to dynamic. We would continue to register MAC addresses, but if a static IP address is needed it would have to be specifically requested. This would make the data entry process for the MAC addresses somewhat easier. At the same time, we would begin going through all the IP subnets on campus working with the Tier 1.s and users to make sure we have identified all devices/computers requiring static IP assignments. We will move those to contiguous IP address blocks in all subnets on campus. This will allow us to have the IP addresses not requiring static assignments in contiguous blocks next to the existing contiguous dynamic blocks in each subnet.

The second step will be to covert the current dynamic IP address pools to allow any MAC address to obtain an IP address, not just ones that have been registered. We will then convert the addresses not requiring static assignments to dynamic. After this, the only registrations required would be for devices/systems requiring static IP address assignments. We will also remove the private IP network for unregistered computers, since it will be unnecessary.

The end result will be the majority of devices/computers would work with no registration and the static assignments needed could be handled directly by Network Management. Many of these also require specific network location knowledge, from Network Management, and coordination with other groups, like Enterprise Security, for definition of firewall rules to allow different levels of access.